This invention relates to the production line manufacture of cabinets for such products as refrigerators, freezers, and composite refrigerator-freezers, for example, wherein the outer shells or wrappers are prepainted on one face thereof at the time they are introduced to the manufacturing line. The use of prepainted sheet material saves the considerable cost of later painting the formed cabinet, and, because of the considerable interest these days in the construction of refrigerators, freezers, ovens and the like by manufacturers of such equipment in high-speed production lines, it has become necessary to provide a reliable, economical process to permit the welding of parts such as the galvanized back panel and deck, directly to the prepainted shell or wrapper of the particular appliance cabinet being manufactured.
The use of a welding process, as opposed to a clinching and/or staking process, permits the formation of a more rigid cabinet for subsequent fabrication and assembly, and a product free of external blemishes.
One of the prime objects of the present invention is to provide an improved method of forming prepainted metal cabinets which are painted only on the exterior wall surface thereof, and which may have some non-painted galvanized parts, such as back panels which are required to be secured to the cabinet wrapper.
A further object of the invention is to provide an improved process for fabricating such cabinets or shells which forms a more rigid cabinet and offers a superior product which is free of the external markings characteristic of the clinching and/or staking method which has been used.
Still another object of the invention is to provide a high production process which achieves the welding of galvanized back panels, for instance, to the outer shell wrapper in a manner which leaves the product free of external burn marks or blemishes.